Comprehensive Analysis of the Kiwi Vacuum Extractor in Vaginal Operative Delivery
Release time:
2025-07-09
A vacuum extractor consists of three essential components: the suction cup, a flexible rubber tubing, and a vacuum-generating device. It is employed when a woman experiences difficult labor. During delivery, persistent occipito-posterior or occipito-transverse positions constitute abnormal labor; severe cases often necessitate cesarean section. However, cesarean delivery is associated with slower recovery and higher complication rates. Timely and effective intervention during labor can therefore markedly improve maternal–neonatal outcomes.
A vacuum extractor consists of three essential components: the suction cup, a flexible rubber tubing, and a vacuum-generating device. It is employed when a woman experiences difficult labor. During delivery, persistent occipito-posterior or occipito-transverse positions constitute abnormal labor; severe cases often necessitate cesarean section. However, cesarean delivery is associated with slower recovery and higher complication rates. Timely and effective intervention during labor can therefore markedly improve maternal–neonatal outcomes.
Traditionally, obstetric forceps have been the primary instrument for vaginal operative delivery. Forceps-assisted delivery, however, demands exceptional technical skill and carries a steep learning curve. Improper application can inflict unpredictable neonatal injuries, increase the likelihood of perineal lacerations or episiotomy extensions, and intensify maternal pain [1].
With advances in obstetrics, the single-use, sterile Kiwi vacuum extractor—characterized by its simple operation and lower risk profile—has gained widespread clinical acceptance. It has demonstrated notable efficacy in facilitating delivery while enhancing both delivery quality and safety. This paper reviews the history, advantages, indications, and operative technique of the Kiwi vacuum extractor, as detailed below.
Operating Procedure for the Kiwi Omni Vacuum Extractor
The Kiwi Omni vacuum extractor is a single-unit device comprising a soft silicone suction cup and a rigid stem that incorporates a manual vacuum pump handle, traction mechanism, and traction-force indicator [6].
Step-by-step technique
1. Pre-use preparation
• Perform a vaginal examination and insert an indwelling catheter to empty the bladder.
• Confirm full cervical dilatation and place the woman in the lithotomy position.
• Determine fetal head position and station; disinfect the perineum with povidone-iodine and apply the same solution as lubricant.
2. Application of the cup
• Insert the cup so that its centre lies over the flexion point on the fetal scalp.
• Inspect the inside of the cup to be sure no maternal soft tissue is trapped.
3. Creating the vacuum
• Generate negative pressure with the manual pump to 40–66 kPa (300–500 mmHg); avoid higher pressures.
4. Traction
• During a uterine contraction, grip the pump handle and apply steady traction in the axis of the birth canal.
• The non-dominant hand stabilises the cup.
• Continue controlled traction until the fetal head is delivered.
01 Pre-procedure assessment
A. Maternal evaluation
• Review all antenatal co-morbidities and current clinical status to exclude contraindications to vaginal delivery.
• Evaluate progress of labour; if slow, reassess risk to mother and fetus and institute corrective measures.
• Because maternal pushing effort influences outcome, consider neuraxial analgesia or oxytocin augmentation as appropriate to minimise maternal and neonatal injury [7].
B. Cephalopelvic assessment
• Exclude cephalopelvic disproportion by vaginal examination; if present, proceed to cesarean section.
• Evaluate fetal position, station, caput succedaneum, degree of moulding, and estimated fetal weight (EFW) by ultrasound.
• Macrosomia increases the risk of failure and may be an indication for cesarean delivery.
02 Prerequisites for Kiwi Omni vacuum extraction
1. Informed consent
• Discuss risks, benefits, and alternatives with the woman and her family; obtain explicit consent.
• Respect a request for cesarean section if made.
2. Operator competence
• Success rate and fetal injury depend on the operator’s ability to interpret maternal–fetal status, master insertion technique, and apply correct traction [8].
3. Selection criteria
• Vertex presentation.
• Cephalopelvic proportion confirmed.
• Cervix fully dilated.
• Station at or below the pelvic floor.
• Skilled operator available.
• If progress remains unsatisfactory after a reasonable trial, abandon the procedure and proceed to cesarean section with maternal consent [9].
03 Indications, contraindications, and complications
Indications
• Suspected fetal distress in the second stage.
• Maternal medical conditions (diabetes, hypertension, cardiac disease, asthma) requiring shortening of the second stage.
• Inefficient uterine contractions or maternal exhaustion leading to prolonged second stage.
• Scarred uterus (previous cesarean or myomectomy) to minimise stress on the scar.
• Second-stage arrest (≥2 h with regional anesthesia or ≥1 h without) due to persistent occipito-transverse or occipito-posterior positions when manual rotation fails [10].
Contraindications
• Cervix not fully dilated or high fetal station.
• Malpresentation or cephalopelvic disproportion.
• Macrosomia or gestation <34 weeks.
• Obstructed labour.
• Uterine prolapse.
• History of vesicovaginal fistula repair.
• Severe fetal distress mandating immediate delivery [11].
Complications
• Fetal: intracranial hemorrhage (especially with prolonged traction or malposition), scalp hematoma, caput succedaneum; rare calvarial fracture [12].
• Maternal: vaginal or cervical lacerations from entrapment of soft tissue in the cup.
Most scalp swellings resolve spontaneously within 4 weeks; intracranial injury is uncommon when guidelines are followed.
Therefore, the following precautions must be observed when using the Kiwi Omni vacuum extractor:
1. Precise cup placement
Position the cup exactly on the fetal flexion point to minimize the presenting diameter. The axis of the extractor should remain as parallel as possible to the maternal pelvic axis so that traction force is controlled and both efficacy and safety are optimized.
2. Limit application time
Cup adhesion to the fetal scalp should not exceed 10–15 minutes to prevent scalp injury.
3. Convert promptly if traction is difficult
If traction becomes difficult, immediately inform the woman and her family of the situation and proceed without delay to cesarean section.
4. Correct traction technique
Apply traction strictly along the pelvic axis, synchronizing with the frequency and intensity of uterine contractions to avoid cup dislodgement [14].
5. Post-procedure care
Obstetricians and neonatologists must examine both mother and newborn for birth trauma. Scalp hematomas usually resolve spontaneously; larger or symptomatic hematomas require appropriate management. After delivery, closely monitor the neonate for hyperbilirubinemia and subgaleal hemorrhage; treat promptly if either develops.
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